Science You Can Use: Your cancer-fighting breastmilk

Written by Tanya Lieberman, IBCLC

The news about breastmilk’s cancer-fighting properties has been coming fast and furious recently, and I thought it would be a good idea to recap some of the most interesting findings:

HAMLET – Short for Human Alpha-lactalbumin Made LEthal to Tumor cells, HAMLET is an combination of oleic acid and the protein alpha-lactalbumin, which induces cell death (apoptosis), but leaves healthy cells alone. HAMLET has been shown to kill over 40 different types of cancer cells, including tumors in the lungs, kidneys, prostate, ovaries and bowel, as well as melanoma and leukemia. It has been shown to reduce the growth of a type of brain tumor in animal studies, and in human studies has shown good results in the treatment of a type of skin cancer and bladder cancer. In 2011 the researchers who discovered HAMLET reported that they have succeeded in mapping how it kills tumor cells, in part by cutting altering the cells’ ability to make energy. “Within one hour,” the researchers say, “the cell’s energy supply is cut off.” They believe that the protein complex is not formed until the milk is in the baby’s stomach.

TRAIL – Short for TNF-related apoptosis inducing ligand, TRAIL is a pleiotropic cytokine – a type of protein that has a specific effect on the interactions or communication between cells. TRAIL plays an important role in the immune system and in regulating cell growth and death in different organs and tissues. “The best characterized activity of TRAIL,” say the authors of a 2012 paper, “is to kill cancer cells,” and studies are underway to determine if TRAIL can be used to treat breast and ovarian cancer. The researchers found that TRAIL is present in colostrum and breastmilk at 400 and 100 times the amounts in blood, respectively. No TRAIL was detected in formula. These were the highest measured levels of TRAIL found in any human fluid. The surprisingly high levels of TRAIL in colostrum and mature milk “were in the range of concentrations that are able to kill cancer cells.” The authors are now studying levels of TRAIL in preterm milk.

Elf5 – The most recently reported cancer-fighter is Elf5, a protein that is necessary for lactation in mammals, which suppresses the spread of breast cancer, according to a 2012 study. While not exactly a component of breastmilk, this protein is a necessary part of the process of making milk, and “inhibits the critical cellular transition that is an early indicator of breast cancer and metastasis.” One author explains: “We found that when Elf5 levels are low or absent, epithelial cells become more like stem cells, morphing into mesenchymal cells, changing their shape and appearance and migrating elsewhere in the body. This is how cancer spreads.”

Breastmilk as risk detector- As I’ve written before, breastmilk may hold important clues to a mother’s individual cancer risk. Breast cells are key to undertanding breast cancer, and they’re hard to get without invasive procedures. But these cells naturally exfoliate into our milk in large numbers, and research at the University of Massachusetts have shown that the patterns of DNA changes in them is associated with breast cancer risk. (If you’d like to participate in this research by donating a sample, please see the UMass Breastmilk Lab’s website). One day our milk may be able to tell us about our breast cancer risk, and these findings may pave the way for new treatments, too.